When Carbon dioxide is passed through water for short time (limited supply)
When CO2 is passed through water for short period of time (limited supply) it react and forms calcium carbonate which is insoluble in water and hence the solution becomes turbid or forms a milky white precipitate. The reaction is given as :
Ca(OH)2 (aq) + CO2 (g) → CaCO3 (s) + H2O
When Carbon dioxide is passed through water for long time (excess supply)
When CO2 is passed through lime water in excess, the turbidity disappears as the calcium bicarbonate gets formed which is soluble in water and hence a clear solution is observed. The reaction is given as
CaCO3 (s) + H2O (l) + CO2 (g) → Ca(HCO3)2 (aq)